1. Field of the Invention
The invention relates to an arrangement for generating an analog or digital I/Q signal for an I/Q modulator, which signal is composed of two or more data streams processed by identical or different digital modulation methods.
2. Description of the Related Art
In modern transmission engineering, I/Q signals are used for data transmission that are modulated onto a high-frequency carrier in an I/Q modulator. There are extremely diverse modulation standards for the I/Q modulator for generating said I/Q signals. A frequently used modulation method is, for example, the time-division multiplex access method TDMA used in Europe and the USA for mobile-radio purposes or the code division multiplex method CDMA. In such systems, it is often desirable to transmit, via one and the same high-frequency carrier and using the same I/Q modulator, two or more I/Q signals that have been processed according to the same digital modulation standard, but with different input data streams, or that have been processed according to different digital modulation standards. Said different I/Q signals can each be generated separately in respective modulation encoders or modulation generators and then added; however, this is relatively expensive.